I have a simple tableViewCell build in interface builder. It contains a UIView which contains an image. Now, when I select the cell, the default blue selection background is
From that you said you built a tableViewCell using IB, I'd like to check whether you are adding your view as a subview of contentView of UITableViewCell, not view. The content view is the default superview for content displayed by the cell.
From the reference:
The content view of a UITableViewCell object is the default superview for content displayed by the cell. If you want to customize cells by simply adding additional views, you should add them to the content view so they will be positioned appropriately as the cell transitions into and out of editing mode.